English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We have constructed an approximate microscopic model for the neutron dynamicstructure factor of solid methane in phase II. We expect our model to apply forneutron energies below 1\textit{eV} at pressures near 1 bar and temperaturesbelow 20K, where solid methane exists in a phase, called phase II, in which thetetrahedral hydrogens exist in a mixed phase of free rotors and hinderedrotors. Certain matrix elements needed for the dynamic structure factor $S(Q,\omega)$ are adapted from a calculation by Ozaki \textit{etal.}\cite{ozaki:3442}\cite{ozaki2}. The model treats the effects of moleculartranslations, intramolecular vibrations and the free and hindered rotationaldegrees of freedom as uncoupled ones. Total scattering cross sectionscalculated from the model agree with the cross section measurements ofGrieger\cite{grieger:3161} and Whittemore\cite{Wittemore} for the incidentneutron energies of 0.5 \textit{meV} $\sim$ 1\textit{eV}. The effective densityof states extracted from the model was compared with the Harker $&$ Bruggerfrequency spectrum extracted from neutron scattering measurements conducted at22K\cite{HARKER1967}.

A Microscpoic Model for the Neutron Dynamic Structure Factor of Solid Methane in phase II